The present invention relates generally to torsion damping assemblies comprising two coaxial members rotatably mounted relative to each other with circumferentially disposed resilient means interposed therebetween, including a first member comprising a hub and a web extending radially from the hub, and a second member comprising at least one annular plate member disposed annularly about the hub, parallel to the web, the resilient means comprising springs disposed in part in cutouts in the web and in part in openings or cutouts in the annular plate member or members.
Such torsion damping assemblies may be used for torsion damping hubs of friction clutch assemblies for motor vehicles.
In such torsion damping assemblies which are intended to be fitted on heavy vehicles a problem arises, namely, the springs are interposed between two coaxial members of such an assembly, bearing on the hub web of one of the members against an edge defining the openings in the web in which they are accommodated. It is important that the edge has a sufficient thickness; in other words, the hub web must have a thickness great enough for the hub web to be able to transmit to the hub the torque applied by the springs.
Now the cutouts in the hub web in which the springs are accommodated are usually punched, by present day punching techniques do not usually enable punching thick webbed hubs. Accordingly the maximum possible hub web axial thickness it is possible to obtain by punching is limited.